1. Technical Field
The present disclosure relates to actuators, and particularly, relates to a piezoelectric actuator.
2. Description of Related Art
Many camera modules have zooming and/or autofocus functions. A typical camera module employs a piezoelectric actuator to drive a lens unit to move along an optical axis to perform the zoom/focusing functions. The piezoelectric actuator includes a fixed member, a movable member movably received in the fixed member, and a piezoelectric member fixed on the fixed member and contacted with the movable member. The piezoelectric actuator further employs two magnets for providing a preload force on the piezoelectric member and the movable member to drive the piezoelectric member to be in contact with the movable member.
However, in order to receive the magnets, a total length of the camera module increases, which is not beneficial for the pursuit of miniaturization of the camera module. In addition, the movable member is limited to a material that can be inter-attractive with the magnets.
What is needed therefore is a piezoelectric actuator addressing the limitations described.